JP2014146876A - Message distribution system and message distribution method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a message distribution system and a message distribution method capable of reducing the resource consumption and communication load of a push server in a push message delivery using an IP network.SOLUTION: A message distribution system comprises: a distribution device 10 including a message transmission unit 11 for transmitting a message in push type via a connection if the connection is established between its own device and a destination communication terminal upon receiving a message transmission request addressed to the communication terminal, otherwise transmitting a trigger for requesting connection to the destination communication terminal; and communication terminals 20-1 through 20-n including message reception units 21-1 through 21-n for establishing connection with the distribution device 10 upon receiving a trigger therefrom, acquiring a message addressed to its own terminal from the distribution device 10 via the connection, and maintaining the connection after acquiring the message.

Description

  The present invention relates to a message delivery system and a message delivery method that perform push-type message delivery.

  As a method for sending a message from a server to a client using a network such as an IP (Internet Protocol) network or a cellular phone network, a message is sent from the server to the client without being requested by the client. Message transmission method (hereinafter simply referred to as server-based message transmission). As a response to a message transmission request from the client, there is a “client-origin message acquisition method (hereinafter simply referred to as client-origin message acquisition)” in which a message is transmitted from the server to the client. FIG. 11 is an explanatory diagram showing a state of message transmission / reception by server-origin message transmission and client-origin message acquisition.

  In the server-origin message transmission shown in FIG. 11A, the client always waits for a message. The server can send a message to the client at any time. Server-origin message transmission is a push-type message transmission in a narrow sense in which a connection is established from a server when a message is transmitted without maintaining a connection between the client and the server. As an example of server-origin message transmission, there is message transmission by a short message service (SMS) using a mobile phone line. As another example, there is a method in which the client side waits for a TCP connection, and a TCP connection is made from the server to the client.

  In server-origin message transmission, although message transmission that does not depend on a request from a client, that is, push-type message transmission can be realized, there are the following problems.

  For example, a TCP connection, a UDP connection, and a connection using a Raw IP packet from the server to the client can be an attack means to the client, and therefore may be blocked by a network device in order to avoid an attack by a third party. Further, even if TCP connection or the like from the server to the client is permitted without being blocked by the network device, there is a possibility that the client operates abnormally due to message transmission by a malicious third party. The abnormal operation of the client is, for example, transmission of personal information stored in the client to an external site.

  For example, when a mobile communication terminal receives a short message by SMS, the mobile communication terminal needs to be connected to a mobile telephone network. That is, when the mobile communication terminal is not connected to the mobile phone network, the mobile communication terminal cannot receive the short message. In SMS, the mobile communication terminal can only receive short text messages.

  In the message acquisition from the client shown in FIG. 11B, when the client acquires a message from the server, a message acquisition request is transmitted from the client to the server, and the content of the message is included in the response (response). . An example of client-origin message acquisition is message acquisition using HTTP (HyperText Transfer Protocol). Typically, the message acquisition request and the response are transmitted and received through the same connection, for example, a TCP connection. The shaded portions in FIG. 11B represent the same connection.

  Push-type message transmission can be realized in a pseudo manner by modifying the client-origin message acquisition as shown in FIG. 11B as follows.

(1) Periodic polling method In the periodic polling method, a client acquires a message from the server by sending a message acquisition request to the server at regular time intervals. That is, in the periodic polling method, a connection with the server is established at regular intervals led by the client, and the client acquires messages stored in the server. In this method, the message arrives at the client only when the client transmits a message acquisition request.

  FIG. 12 is an explanatory diagram showing a state of message transmission / reception by the periodic polling method using HTTP. The client transmits an HTTP request to the server at regular time intervals (polling period). When a message addressed to the client is stored in the server, the HTTP response includes the content of the message. Otherwise, an empty HTTP response is returned.

  The periodic polling method has a problem that communication traffic that does not contribute to message transmission occurs because a message acquisition request is sent at regular intervals even when there is no message addressed to the client. In addition, there is a problem that a delay corresponding to the polling interval occurs at a maximum from when the message is accumulated in the server until the client acquires the message.

(2) Connection maintenance method In the connection maintenance method, the connection established by the client is maintained for a long time. Through that connection, the server sends a message to the client. Unlike periodic polling, the connection is always maintained, so the server can send a message to the client at any time.

  As an example of the connection maintenance method, a long polling method (hereinafter simply referred to as long polling) is known. FIG. 13 is an explanatory diagram showing a state of message transmission / reception by long polling.

  In long polling, the client sends an HTTP request to the server. The server returns an HTTP response when the message addressed to the client arrives at the server or when a certain time has elapsed and timed out. In the former case, the HTTP response includes the contents of the arrived message. In either case, after receiving the HTTP response, the client sends an HTTP request to the server again and repeats the same operation.

  In general, long polling is often used in combination with HTTP Keep-Alive described in Non-Patent Document 1 in order to reduce communication traffic associated with TCP connection establishment / disconnection. HTTP keep alive is a function of reusing the same TCP connection.

  In the connection maintenance method, it is necessary to always maintain a connection between all clients and servers regardless of whether or not a message is transmitted. Therefore, there is a problem that server resources having a size (size) proportional to the number of clients, mainly memory, are always occupied.

  Patent Document 1 describes a method in which trigger transmission from a server origin and message acquisition from a client origin are combined. In the method described in Patent Document 1, after the client receives the trigger transmitted from the server, the message body is acquired at the client starting point. Therefore, according to the method described in Patent Document 1, it is possible to solve problems caused by server-origin message transmission, such as attacks from malicious third parties and message size limitations described above.

  Patent Document 2 describes a system in which a content server that provides content information distributes updated content information to a user terminal in a push manner via a push server in response to a call from the user terminal. . In the system described in Patent Document 2, when content information is updated in the content server, the content server notifies the push server of a call request. The push server transmits a trigger message to the user terminal in response to the notified call request. The user terminal calls the content server in response to the received trigger message, and acquires updated content information from the content server.

JP 2004-129084 A JP 2002-344529 A

RFC 2616 “Hypertext Transfer Protocol—HTTP / 1.1”, Internet Engineering Task Force, 1999.

  FIG. 14 is an explanatory diagram showing a state of message transmission / reception by a method combining trigger transmission from the server origin and message acquisition from the client origin. In the method described in Patent Document 1, as shown in FIG. 14, when the server sends a message to the client, the server sends a short message called a trigger to the client using a message sending means. Here, no message is included in the trigger itself. The client that has received the server-origin trigger acquires a message addressed to the client by sending a message acquisition request to the server.

  When the method shown in FIG. 14 is used, a message can be delivered to the client at an arbitrary timing. In addition, it is possible to maintain higher resistance against attacks by malicious third parties than when using only a server-origin message transmission method. The reason is that since the message itself is acquired from the client, it is possible to take measures such that the client does not send a message acquisition request to a server other than the trusted server.

  Further, the method shown in FIG. 14 does not need to always maintain a connection between the client and the server, and therefore has an advantage that a server resource for maintaining the connection is not required as in the case of server-origin message transmission.

  However, in order to deliver a message to the client, two types of communication, that is, communication by “server-origin trigger transmission” and communication by “client-origin message acquisition” are required. Therefore, when this method is used, communication traffic that is twice as much as the communication traffic necessary for transmitting the message itself is generated. That is, communication traffic is generated up to twice as much as push message delivery in a narrow sense. Therefore, this method has problems in terms of client power consumption and network load.

  Therefore, an object of the present invention is to provide a message delivery system and a message delivery method that can reduce resource consumption and communication load of a push server in push-type message delivery using an IP network.

  The message delivery system according to the present invention includes a delivery device for delivering a message and a communication terminal. When the delivery device accepts a message transmission request addressed to the communication terminal, a connection is established between the own device and the destination communication terminal. If the connection is established, a message is sent through the connection in a push type. If the connection is not established, a message transmission unit that sends a trigger for requesting the connection to the destination communication terminal is provided. Including a message receiving unit that establishes a connection with the distribution device, acquires a message addressed to the terminal through the connection from the distribution device, and maintains the connection after acquiring the message. It is characterized by including.

  In the message delivery method according to the present invention, when a delivery apparatus that performs message delivery accepts a message transmission request addressed to a communication terminal, the connection is established when the connection is established between the own apparatus and the destination communication terminal. If the connection is not established, a trigger for requesting a connection is transmitted to the destination communication terminal. When the communication terminal receives the trigger from the distribution device, the distribution device Is established, a message addressed to the terminal is acquired from the distribution device through the connection, and the connection is maintained after the message is acquired.

  According to the present invention, it is possible to reduce resource consumption and communication load of a push server in push-type message distribution using an IP network.

It is a block diagram which shows the structure of 1st Embodiment of the message delivery system by this invention. It is explanatory drawing which shows an example of the information stored in a connection state memory | storage part. It is explanatory drawing which shows an example of the information stored in a message storage part. It is a flowchart which shows operation | movement of a push message transmission part. It is a flowchart which shows operation | movement of a message acquisition request process part. It is a flowchart which shows operation | movement of a connection control part. It is a flowchart which shows the operation | movement of the push message reception process in the message receiving part of a mobile communication terminal. It is explanatory drawing which shows the mode of the message acquisition by the combination of long polling and HTTP keep alive. It is a block diagram which shows the minimum structure of the message delivery system by this invention. It is a block diagram which shows the other minimum structure of the message delivery system by this invention. It is explanatory drawing which shows the mode of the message transmission / reception by message transmission of a server origin, and message acquisition of a client origin. It is explanatory drawing which shows the mode of the message transmission / reception by the periodic polling system using HTTP. It is explanatory drawing which shows the mode of the message transmission / reception by long polling. It is explanatory drawing which shows the mode of the message transmission / reception by the method which combined the trigger transmission of a server origin, and the message acquisition of a client origin.

Embodiment 1. FIG.
A first embodiment of the present invention will be described below with reference to the drawings.

  In this embodiment, when a push server receives a message transmission request addressed to a specific mobile communication terminal for the first time, it transmits a trigger to the mobile communication terminal. Then, the mobile communication terminal that has received the trigger establishes a connection with the push server. After the connection is established, the push server transmits a message to the mobile communication terminal through the connection. The push server and the mobile communication terminal maintain this connection for a certain time. When the push server receives a subsequent message transmission request addressed to the mobile communication terminal while the connection is maintained, the push server does not use a trigger and transmits a message using the established connection. If there is no message transmission request addressed to the mobile communication terminal for a certain period of time, the push server disconnects the connection and releases server resources for maintaining the connection.

  Thus, in the message delivery system according to the present invention, the push server transmits a message through a temporarily valid connection, and transmits a trigger to the mobile communication terminal only when there is no connection. Encourage the establishment of a connection. By operating in this way, the message delivery system according to the present invention enables efficient message delivery with low resource consumption and communication load of the push server.

  In the present embodiment, the communication method necessary for transmitting the message itself is referred to as the first communication method. The communication method used for trigger transmission is called a second communication method.

  FIG. 1 is a block diagram showing a configuration of a first embodiment of a message distribution system according to the present invention. As shown in FIG. 1, the message delivery system according to the present invention includes a push server 100 and mobile communication terminals 200-1 to 200-n.

  At least one mobile communication terminal is connected to the push server 100. The push server 100 and the mobile communication terminals 200-1 to 200-n are connected via a packet communication network 400 such as a mobile phone network or a wireless LAN.

  In addition, at least one application server is connected to the push server 100. The push server 100 and the application servers 300-1 to 300-n are connected via an arbitrary network (not shown) such as the Internet.

  The push server 100 is a server device that operates under program control, and performs push-type message delivery to the mobile communication terminals 200-1 to 200-n based on requests from the application servers 300-1 to 300-n. .

  The push server 100 includes a push message transmission unit 110, a message acquisition request processing unit 120, a connection control unit 130, a connection state storage unit 140, and a message storage unit 150.

  When the push message transmission unit 110 receives a push message transmission request (hereinafter also simply referred to as a message transmission request) from the application servers 300-1 to 300-n, the push message transmission unit 110 transmits the request to the destination mobile communication terminal (hereinafter referred to as the destination terminal). Send a message. When there is no connection with the destination terminal, the push message transmission unit 110 transmits only a trigger to the destination terminal and does not transmit a message. In this case, the message that has not been transmitted is transmitted as a response to the message acquisition request from each mobile communication terminal.

  The message acquisition request processing unit 120 receives a message acquisition request from each mobile communication terminal, and transmits a message to the requesting mobile communication terminal as a response to the message acquisition request.

  The connection control unit 130 monitors whether or not the expiration date has expired at regular time intervals for the connection established between each mobile communication terminal and the push server 100. When the connection control unit 130 detects a connection that has expired, the connection control unit 130 disconnects the connection.

  The connection state storage unit 140 stores information regarding the connection state of each mobile communication terminal. FIG. 2 is an explanatory diagram illustrating an example of information stored in the connection state storage unit 140.

  As shown in FIG. 2, the connection state storage unit 140 includes a terminal ID for uniquely identifying the mobile communication terminals 200-1 to 200-n and attributes (connection state, connection ID, expiration date) corresponding to the terminal ID. Hold the containing record. In other words, the connection state storage unit 140 holds each attribute of “connection state”, “connection ID”, and “expiration date” using the terminal ID as a key.

  “Connection state” indicates whether or not a connection exists between the mobile communication terminal identified by the terminal ID and the push server 100. At the time of record registration, “connected” is set as the “connection state”. Specifically, when the connection control unit 130 detects a connection established with a certain mobile communication terminal as a starting point, a record including a terminal ID corresponding to the mobile communication terminal is stored in the record held by the connection state storage unit 140. Search from inside. When there is a record including the terminal ID, the connection control unit 130 changes the “connection state” of the record from “not connected” to “connected”. If there is no record corresponding to the terminal ID, the connection control unit 130 adds a record corresponding to the mobile communication terminal to the connection state storage unit 140. Further, the connection control unit 130 sets the “connection state” of the record to “connected”.

  When the “connection state” is “connected”, an ID that uniquely identifies the connection, for example, a file descriptor that identifies the socket is set as the “connection ID”. As the “expiration date”, a time indicating the expiration date of the connection (hereinafter also referred to as a timeout value) is set. In the present embodiment, a time when a predetermined time, for example, 10 minutes elapses from the time when the connection is detected is set as the “expiration date”.

  An example of the terminal ID is an ID that permanently identifies the mobile communication terminal, such as a telephone number or IMEI (International Mobile Equipment Identity). A temporary terminal ID may be assigned to the mobile communication terminal for the purpose of preventing malicious message transmission. The terminal ID may be an ID that uniquely identifies an application that operates on the mobile communication terminal.

  The message storage unit 150 stores information related to the push message transmission request received from the application server. FIG. 3 is an explanatory diagram illustrating an example of information stored in the message storage unit 150.

  As shown in FIG. 3, the message storage unit 150 stores a record including a message ID for uniquely identifying a message and attributes (date and time, transmission state, sender ID, destination terminal ID, message body) corresponding to the message ID. Hold. That is, the message storage unit 150 uses the message ID as a key, and retains the attributes of “date and time”, “transmission state”, “sender ID”, “destination terminal ID”, and “message body”.

  “Date and time” indicates the date and time when the push message transmission request for the message identified by the message ID is received. “Transmission state” indicates whether or not transmission of the message to the destination terminal is completed. Specifically, when the transmission is completed, “transmitted” is set as the “transmission state”. If transmission has not been completed, “not transmitted” is set as the “transmission state”. “Sender ID” is an ID for identifying the sender of the push message transmission request. “Destination terminal ID” is the terminal ID of the mobile communication terminal that is the destination of the message, that is, the destination terminal. “Message body” is the body of the message to be transmitted to the destination terminal.

  The push message transmission unit 110, the message acquisition request processing unit 120, and the connection control unit 130 are realized by a computer that operates according to a program, for example. In this case, the CPU reads the program and operates as the push message transmission unit 110, the message acquisition request processing unit 120, and the connection control unit 130 according to the program. In addition, the push message transmission unit 110, the message acquisition request processing unit 120, and the connection control unit 130 may be realized by separate hardware.

  The connection state storage unit 140 and the message storage unit 150 are realized by a storage device such as a RAM (Random Access Memory) included in the push server 100, for example.

  The mobile communication terminals 200-1 to 200-n are devices that can communicate with the push server 100 via the packet communication network 400. The mobile communication terminals 200-1 to 200-n are, for example, in-vehicle information terminals incorporating a mobile phone, a smartphone, and a communication module. Each of the mobile communication terminals 200-1 to 200-n includes a message receiving unit.

  The message receiving units 210-1 to 210-n send a message acquisition request to the push server 100 and receive a message addressed to the own terminal from the push server 100.

  Note that the message receiving units 210-1 to 210-n are realized by, for example, a computer that operates according to a program. In this case, the CPU reads the program and operates as the message receiving units 210-1 to 210-n according to the program.

  The application server 300 transmits a push message transmission request to the push server 100 in order to transmit a message to each mobile communication terminal.

  Next, the operation of this embodiment will be described.

  First, the operation of the push message transmission unit 110 will be described. FIG. 4 is a flowchart showing the operation of the push message transmission unit 110.

  The push message transmission unit 110 issues a unique message ID for the received push message transmission request. The push message transmission unit 110 saves the destination terminal ID, the message body, the sender ID, and the date and time included in the push message transmission request as a new record in the message storage unit 150 together with the issue of the message ID (step S401).

  In step S401, the push message transmission unit 110 sets “not transmitted” as the “transmission state” of the new record.

  The push message transmission unit 110 searches the connection state storage unit 140 using the destination terminal ID included in the push message transmission request as a key, and refers to the connection state of the mobile communication terminal (destination terminal) corresponding to the destination terminal ID (step). S402). At this time, the push message transmission unit 110 confirms whether or not there is an established connection between the destination terminal and the push server 100 (step S403).

  If there is no established connection (NO in step S403), the push message transmission unit 110 proceeds to the process in step S409.

  If there is an established connection (YES in step S403), the push message transmission unit 110 uses the connection with the destination terminal to respond to the push message transmission request stored in the message storage unit 150 in step S401. The included message is transmitted to the destination terminal (step S404).

  If the message transmission to the destination terminal is successful in step S404 (YES in step S405), the “transmission state” of the record saved in the message storage unit 150 in step S401 is changed to “sent” (step S406). .

  After executing the process of step S406, the push message transmission unit 110 executes a process for extending the validity period of the connection (step S407), and ends the message transmission process. In step S407, the push message transmission unit 110 updates the “expiration date” value of the record corresponding to the destination terminal stored in the connection state storage unit 140 to a time after a predetermined time has elapsed from the current time. . Here, the reason why the effective period of the connection is extended is that the use of one service typically involves sending and receiving a plurality of messages.

  When the message transmission to the mobile communication terminal fails in step S404 (NO in step S405), the push message transmission unit 110 stores the “connection state” of the record corresponding to the destination terminal stored in the connection state storage unit 140. Is updated to “not connected” (step S408). That is, for the invalid connection, the push message transmission unit 110 matches the contents of the connection state storage unit 140 with the actual connection state. Here, as an example of a case where message transmission fails, there is a case where the connection becomes invalid and message transmission fails due to the expiration of the address conversion table in the NAT device.

  After executing the processing of step S408, the push message transmission unit 110 transmits a trigger for requesting establishment of a connection to the destination terminal using the second communication method, that is, the message transmission method originating from the server. (Step S409), the message transmission process is terminated.

  In step S401, the push message transmission unit 110 stores a new record in the message storage unit 150 regardless of whether or not the message transmission through the established connection is successful. In step S409, the push message transmission unit 110 performs trigger transmission. A new record may be stored only when it is executed.

  Next, the operation of the message acquisition request processing unit 120 will be described. FIG. 5 is a flowchart showing the operation of the message acquisition request processing unit 120.

  When receiving the trigger from the push server 100, the mobile communication terminals 200-1 to 200-n establish a connection with the push server 100. The mobile communication terminals 200-1 to 200-n transmit a message acquisition request to the push server 100 after establishing a connection. The message acquisition request includes a terminal ID that identifies the mobile communication terminal as a parameter.

  When receiving the message acquisition request, the message acquisition request processing unit 120 searches the message storage unit 150 for a message to be transmitted (step S501). The message to be transmitted is a message in which the value of “destination terminal ID” matches the terminal ID included in the message acquisition request, and the “transmission state” is “unsent”.

  If there is a message to be transmitted as a result of the search in step S501 (YES in step S502), the content of the message is transmitted to the requesting mobile communication terminal as a response to the message acquisition request (step S503). . The message acquisition request processing unit 120 transmits this response through an established connection between the requesting mobile communication terminal and the push server 100.

  If message transmission to the mobile communication terminal fails in step S503 (NO in step S504), the message acquisition request processing unit 120 ends the process for the message acquisition request. An example of the cause of message transmission failure is a situation where the requesting mobile communication terminal is out of the mobile phone network and cannot communicate.

  If the message transmission to the mobile communication terminal is successful in step S503 (YES in step S504), the message acquisition request processing unit 120 stores the record corresponding to the message transmitted in step S503 stored in the message storage unit 150. The “transmission state” is changed to “transmitted” (step S505).

  The message acquisition request processing unit 120 executes the process of extending the validity period of the connection after executing the process of step S505 (step S506), and ends the process for the message acquisition request. In step S506, the message acquisition request processing unit 120 passes the “expiration date” value of the record corresponding to the request source terminal of the message acquisition request stored in the connection state storage unit 140 for a predetermined time from the current time. Update at a later time.

  As a result of the search in step S501, when there is no message to be transmitted (NO in step S502), the message acquisition request processing unit 120 sends a response indicating an error to the mobile communication terminal that has requested the message acquisition request. The message is transmitted (step S507), and the process for the message acquisition request is terminated.

  Next, the operation of the connection control unit 130 will be described. FIG. 6 is a flowchart showing the operation of the connection control unit 130.

  The connection control unit 130 executes the processing shown in FIG. 6 at regular intervals using means such as timer interruption. Here, although the process for one record stored in the connection state storage unit 140 will be described, the connection control unit 130 performs the same process for all the records stored in the connection state storage unit 140.

  The connection control unit 130 refers to “connection state” and “expiration date” for one record stored in the connection state storage unit 140 (step S601).

  If the “connection state” of the record is “connected” and the current time has expired (YES in step S602), the connection control unit 130 proceeds to the process of step S603. In other cases (NO in step S602), the connection control process is terminated.

  In step S603, the connection control unit 130 disconnects the connection between the push server 100 and the mobile communication terminal corresponding to the record.

  In the connection state storage unit 140, the connection control unit 130 changes the “connection state” of the record to “not connected” (step S604), and ends the connection control process.

  Here, when the connection between the push server 100 and the mobile communication terminals 200-1 to 200-n is a TCP connection, the connection disconnection in step S603 is a TCP connection disconnection process starting from the FIN packet transmission from the push server 100. Equivalent to. When the connection is long polling, disconnection in step S603 corresponds to transmission of an HTTP response from the push server 100.

  Next, the operation of the message receiver of each mobile communication terminal will be described. FIG. 7 is a flowchart showing the operation of the push message reception process in the message receivers 210-1 to 210-n of the mobile communication terminals 200-1 to 200-n.

  When the message receiving unit of each mobile communication terminal receives a trigger from the push server 100 or receives a message from the push server 100 through an established connection, it starts the push message receiving process shown below.

  The message receiving unit checks whether or not a connection has been established with the push server 100 (step S701).

  If the connection has not been established (NO in step S701), the message receiving unit establishes a connection with the push server 100 (step S702). If the connection has been established (YES in step S701), the message receiving unit proceeds to the process in step S703. Here, the former corresponds to a case where a trigger is received, and the latter corresponds to a case where a message is received through an established connection.

  The message receiving unit sends a message acquisition request through a connection established with the push server 100, and receives a message addressed to the terminal itself (step S703).

  The message receiving unit maintains an established connection with the push server 100 (step S704).

  Here, the processing of steps S702 to S704 will be described using a specific example of connection.

  For example, when the connection is a TCP connection and data transmission / reception through the connection is realized as packet transmission / reception in the TCP connection, the connection establishment in step S702 corresponds to a TCP 3-way handshake. The message acquired by the message receiving unit in step S703 corresponds to a TCP packet sequence transmitted from the push server 100 as a response to the message acquisition request packet. In step S704, the message receiving unit does nothing.

  For example, when the connection is realized as long polling, the connection establishment in step S <b> 702 corresponds to an HTTP request transmitted from the message reception unit to the push server 100. The message acquired by the message receiving unit in step S703 corresponds to an HTTP response to the HTTP request. The process in step S704 corresponds to a process in which the message receiving unit transmits an HTTP request again after receiving an HTTP response in step S703. Note that the connection is interrupted in the HTTP layer immediately after the completion of the processing in step S703, but the TCP connection can be maintained in combination with the HTTP keep-alive.

  FIG. 8 is an explanatory diagram showing how messages are acquired by a combination of long polling and HTTP keep-alive. When long polling and HTTP keep alive are combined, as shown in FIG. 8, the TCP connection established at the time of the first HTTP request is maintained, and is used in the second and subsequent HTTP requests.

  As described above, in this embodiment, when the push server transmits a message addressed to one of the mobile communication terminals, unlike the method shown in FIG. 14, the mobile communication terminal and the push server In addition to establishing a connection between them, the established connection is maintained for a certain period of time. In addition, the established connection is maintained for a certain period of time, and a message is transmitted using only the connection without using a trigger during the effective period of the connection. As a result, when a subsequent message arrives at the same mobile communication terminal, communication for trigger transmission and connection establishment becomes unnecessary. Therefore, for example, when a message addressed to the same mobile communication terminal is sent a plurality of times within a certain period, communication traffic for sending and receiving triggers can be reduced. As described above, in this embodiment, in push-type message delivery using an IP network, a large number of messages are efficiently delivered while suppressing the hardware resources required to maintain the connection between the mobile communication terminal and the push server. be able to.

  In this embodiment, the connection between the push server and the mobile communication terminal is temporary, and a message addressed to the mobile communication terminal arrives for a certain time, typically several minutes to several tens of minutes. If not, the push server determines that a timeout has occurred and disconnects the connection. If a message addressed to the mobile communication terminal arrives before the timeout occurs, the push server extends the connection validity period. This is because if a message arrives at the same terminal a plurality of times within a certain time, there is a high possibility that a message will arrive soon. By extending the valid period of the connection, communication traffic for trigger transmission / reception can be reduced even when a plurality of messages are transmitted from the same terminal over a certain period of time. On the other hand, the system described in Patent Document 2 does not consider at what timing the connection once established with the user terminal is disconnected. Therefore, in the system described in Patent Document 2, it is difficult to reduce communication traffic for trigger transmission / reception when a plurality of messages are transmitted from the same terminal over a certain period of time.

  In the present embodiment, the case where only one push server is included in the message distribution system has been described. However, any number of push servers may be included in the message distribution system. For example, a plurality of push servers may be arranged in parallel for load distribution.

  INDUSTRIAL APPLICABILITY The present invention can be used for a server device for performing push-type message delivery to a communication device having a communication function such as a mobile phone, a smartphone, a personal computer, an in-vehicle information terminal, a TV, and a sensor.

  FIG. 9 is a block diagram showing the minimum configuration of the message delivery system according to the present invention. FIG. 10 is a block diagram showing another minimum configuration of the message delivery system according to the present invention.

  As shown in FIG. 9, the message delivery system includes a delivery device 10 that performs message delivery (corresponding to the push server 100 shown in FIG. 1), and communication terminals 20-1 to 20-n (mobile communication terminals shown in FIG. 1). 200-1 to 200-n), and the distribution apparatus 10 sends messages addressed to communication terminals from the application servers 30-1 to 30-n (application servers 300-1 to 300-n shown in FIG. 1). When a transmission request is accepted, if a connection is established between the own device and the destination communication terminal, a message is sent in a push type through the connection, and if the connection is not established, A message transmission unit 11 (in the push server 100 shown in FIG. 1) that transmits a trigger for requesting a connection to a destination communication terminal. The communication terminals 20-1 to 20-n receive a trigger from the distribution device 10 and establish a connection with the distribution device 10 and receive messages addressed to the terminal through the connection. Message receiving units 21-1 to 21-n (message receiving units 210-1 to 210-210 in the mobile communication terminals 200-1 to 200-n shown in FIG. 1). Equivalent to -n).

  According to such a configuration, when a subsequent message arrives at the same mobile communication terminal, communication for trigger transmission and connection establishment becomes unnecessary. Therefore, a large number of messages can be efficiently distributed while suppressing the hardware resources required for maintaining the connection between the mobile communication terminal and the push server.

  As shown in FIG. 10, the following message distribution system is also disclosed in the above embodiment. That is, the message delivery system shown in FIG. 9 may further include configurations as shown in the following (1) to (4).

(1) The connection state storage unit 13 (corresponding to the connection state storage unit 140 in the push server 100 shown in FIG. 1) that holds the timeout value indicating the expiration date of the connection established between the distribution device 10 and each communication terminal. ) And the timeout value held in the connection state storage unit 13, and the connection control unit 12 that disconnects the connection after the time indicated by the timeout value (corresponding to the connection control unit 130 in the push server 100 shown in FIG. 1). A message delivery system comprising:

  According to such a configuration, hardware resources required for maintaining the connection between the mobile communication terminal and the push server can be further suppressed.

(2) When the message transmission unit 11 accepts a message transmission request, if a connection is established with the destination notification terminal, a timeout corresponding to the connection held by the connection state storage unit 13 A message delivery system that updates and extends values.

  According to such a configuration, it is possible to reduce communication traffic for trigger transmission / reception even when a plurality of messages are transmitted from the same terminal over a certain time by extending the timeout value of the connection.

(3) A message delivery system that transmits a trigger to a destination communication terminal when the message transmission unit 11 fails to transmit a message through a connection already established with the destination communication terminal.

  According to such a configuration, for example, even when the connection becomes invalid and the message cannot be transmitted due to the expiration of the address conversion table in the NAT device, the message can surely reach the destination mobile communication terminal. .

(4) When the message transmission unit 11 accepts a message transmission request, the message transmission unit 11 refers to the information indicating the presence / absence of a connection with each communication terminal held by the connection state storage unit 13 and communicates with the destination communication terminal. A message delivery system that determines whether or not a connection has been established.

  According to such a configuration, it is possible to accurately manage the presence / absence of connections of a plurality of mobile communication terminals. Accordingly, even when a plurality of mobile communication terminals are connected to the push server, a large number of messages are reliably suppressed while suppressing the hardware resources required to maintain the connection between each mobile communication terminal and the push server. Can be delivered efficiently.

DESCRIPTION OF SYMBOLS 10 Distribution apparatus 11 Message transmission part 12, 130 Connection control part 13, 140 Connection state storage part 150 Message storage part 20-1 to 20-n Communication terminal 21-1 to 21-n, 210-1 to 210-n Message reception Unit 30-1 to 30-n, 300-1 to 300-n application server 100 push server 110 push message transmission unit 120 message acquisition request processing unit 200-1 to 200-n mobile communication terminal

Claims (10)

A delivery device for delivering messages and a communication terminal;
The distribution device includes:
When a message transmission request addressed to a communication terminal is accepted, if a connection is established between the device itself and the destination communication terminal, a message is transmitted through the connection in a push type, and the connection is established. If not, including a message transmission unit that transmits a trigger for requesting a connection to the destination communication terminal,
The communication terminal is
A message receiving unit that, upon receiving the trigger from the distribution device, establishes a connection with the distribution device, acquires a message addressed to the terminal through the connection from the distribution device, and maintains the connection after acquiring the message; A message delivery system characterized by this. The distribution apparatus refers to a connection state storage unit that holds a timeout value indicating an expiration date of a connection established with each communication terminal, and refers to the timeout value held by the connection state storage unit, and the timeout value indicates The message delivery system according to claim 1, further comprising: a connection control unit that disconnects the connection that has passed the time. When a message transmission request is accepted, if a connection is established with the destination notification terminal, the message transmission unit updates and extends the timeout value corresponding to the connection held in the connection state storage unit The message delivery system according to claim 2. The message transmission unit transmits a trigger to the destination communication terminal when the message transmission through the connection already established with the destination communication terminal fails. The message delivery system according to any one of claims. When the message transmission unit receives a message transmission request, the message transmission unit refers to the information stored in the connection state storage unit that indicates the presence or absence of a connection with each communication terminal, and establishes a connection with the destination communication terminal. The message delivery system according to any one of claims 2 to 4, wherein the message delivery system is determined. When a distribution device that performs message distribution accepts a message transmission request addressed to a communication terminal, if a connection is established between the own device and the destination communication terminal, a message is transmitted in a push type through the connection. If the connection is not established, send a trigger to request the connection to the destination communication terminal,
When the communication terminal receives the trigger from the distribution device, it establishes a connection with the distribution device, acquires a message addressed to itself from the distribution device through the connection, and maintains the connection after acquiring the message. A characteristic message delivery method. The message distribution method according to claim 6, wherein the distribution device holds a timeout value indicating an expiration date of a connection established with each communication terminal, and disconnects the connection after the time indicated by the timeout value. The message according to claim 7, wherein when the distribution apparatus accepts the message transmission request and the connection is established with the destination notification terminal, the distribution apparatus updates and extends the timeout value corresponding to the connection. Delivery method. The distribution device transmits a trigger to a destination communication terminal when the transmission device fails to transmit a message through a connection already established with the destination communication terminal. The message delivery method according to claim 1. The distribution device holds information indicating the presence / absence of a connection with each communication terminal, and when receiving a message transmission request, refers to the information indicating the presence / absence of a connection with each communication terminal, The message delivery method according to any one of claims 6 to 9, wherein it is determined whether or not a connection is established with a communication terminal.

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